The Democrats’ hold on the presidency and Congress leaves only one branch of government not firmly in their control. The announcement of Supreme Court Justice David Souter’s retirement in June -- likely to be followed quickly by two other justices -- provides President Obama with an opportunity to begin remaking the third.

Our ideological president has acted consistently since taking office. He’s given us cabinet members such as the Kathleen Sebelius, the most pro-abortion Health and Human Services secretary imaginable, and exerted powers over the private sector (such as firing General Motors’ CEO Rick Wagoner) far beyond those given the president by the Constitution.

Now he will nominate someone for the Supreme Court based on his own ideology, precipitating the most significant political battle of Obama’s first term. It was not always so. At least until about twenty-two years ago.

On September 30, 1987, speaking in support of his nomination of Robert Bork to the Supreme Court, President Reagan noted that former Carter Presidential Counsel Lloyd Cutler had testified in Bork’s behalf. Reagan praised Cutler for supporting someone whose politics differed from his own.

Reagan said Cutler’s praise for Bork was “…in keeping with a well respected tradition that we Americans apply to the selection of Supreme Court justices: a President, whether Republican or Democrat, liberal or conservative, seeks out the best qualified person who generally shares the President’s judicial philosophy.”

Bork’s nomination was rejected after a fight in which the Democrats’ attacks on him were so vicious and outrageous that Bork’s name became a verb.

That fight was purely political: ideology was the Democrats’ concern, not judicial philosophy. Bork was an unabashed conservative who threatened the liberals’ domination of the court.

The retirement of liberal Justice David Souter retirement in June is just the first of gives Obama what will probably be three Supreme Court nominations in his first term. (Two other liberals -- John Paul Stevens who is 89 and Ruth Bader Ginsburg who suffers from pancreatic cancer -- are likely to follow Souter.)

Obama praised Souter as a "fair-minded and independent judge" and said he would nominate a replacement who both respects the Constitution and brings "empathy" and "understanding" to the bench. Webster’s defines “empathy” as “imaginative projection of one’s own consciousness into another being.”

Under Obama’s reasoning, the judge’s job isn’t to interpret the law: the judge should walk a mile in the appellant’s Birkenstocks.

"I will seek someone who understands that justice isn't about some abstract legal theory or footnote in a casebook; it is also about how our laws affect the daily realities of people's lives -- whether they can make a living and care for their families, whether they feel safe in their homes and welcome in their own nation," Obama said.

It’s possible for a layman to see a Supreme Court justice’s job in those terms. But anyone who has studied law -- other than someone who wants to revolutionize our 228-year old legal system -- cannot say what Obama said.

Obama’s statement is not shocking because it is entirely consistent with what he and his running mate promised in the 2008 campaign. But it is offensive to those who believe in the rule of law under the Constitution.

An appellate judge is bound by the facts determined by lower courts and juries. He cannot revisit them or take new evidence. What is “good” or “right” in the eyes of an appellate judge is not the decision he is empowered to make. His sympathies -- if our system is to work as the Constitution, laws and court rules require -- must be irrelevant or the law becomes irrelevant. The “abstract legal theory” and footnotes in a case book that the president speaks of derisively are precisely the business -- the only business -- of a Supreme Court justice.

Obama’s choice to replace Souter won’t be based on judicial philosophy, experience or character. Ideology is the prime criteria the president will use to make the choice. He has said as much. We must take him at his word.

Senate Judiciary Committee Chairman Pat Leahy (D-Vt.) gave a few hints on the other criteria the president will apply. On “Fox News Sunday,” Leahy said he’d like to see more women on the court. And that he’d like to see, “…someone from outside the judicial monastery who has real-life experience.” That echoes what Obama said in one of the presidential debates.

We should expect Obama to nominate someone -- black, Hispanic or female -- who will have all the politically-protected advantages that a minority nominee can bring to the confirmation process. And, as Leahy intimated, Obama will probably nominate someone who lacks judicial experience that can be examined through a long trail of written opinions.

But let’s make no mistake and engage in no pretense: Obama will nominate someone who would be a hard-core hyper-liberal judicial activist. It would be impossible -- unthinkable -- for this president to do otherwise.

And the president is a skillful politician: he won’t nominate Michael Moore or Oprah. The nominee will be someone who will be possible to characterize as a moderate, at least credibly enough to satisfy the media and Senate Democrats. That will be done in every way possible. But it will be a smokescreen beclouding someone whose beliefs are in the mainstream of MoveOn.org’s dogmas.

For Republicans, this nomination will be a defining moment.

Republicans will have to pierce the fog, to probe and demonstrate to Americans what the nominee’s ideology is and judicial activism will be. They need to prove whether he believes that empathy is more important than those abstract legal theories the president is eager to disregard in order to achieve societal change.

And after the nominee is endorsed by Leahy’s committee and the Senate is prepared to vote, they must remember this from a book published in 2006:

As the judicial confirmation process began heating up, I had a conversation with a friend in which I admitted concern with some of the strategies we were using to discredit and block nominees. I had no doubt of the damage that some of Bush’s judicial nominees might do; I would support the filibuster of some of these judges, if only to signal the White House the need to moderate its next selections.

That passage is from Barack Obama’s The Audacity of Hope. Obama voted against cloture (i.e., for continuing a filibuster) on Samuel Alito’s nomination to the Supreme Court.

Under the Senate’s rules, sixty votes are needed to invoke cloture and stop a filibuster, even if the votes against it number fewer than 41. Democratic senators from “Red” states -- Nebraska’s Ben Nelson, Virginia’s Mark Warner and Jim Webb and New Mexico’s Jeff Bingaman to name just a few -- must be put on the spot, as must RINOs such as Maine’s Susan Collins and Olympia Snowe.

If Senate Republicans don’t have the courage to put this to the test, it will be terribly difficult for conservatives to take them seriously on anything else.